There is already known a construction machine including a box-shaped cab in which an operator is seated, such as a wheel loader, a bulldozer and an excavator. The cab of such a construction machine includes a cab frame built by, for instance, welding metal plates. The cab frame is independently coated before being mounted on a vehicle body and a typical coating method for the cab frame is cationic coating according to which the cab frame is immersed in an electrodeposition bath with a material for cationic electrodeposition coating.
In some large-sized construction machines, a seat for a trainer is provided in the cab in addition to an operator seat. In such a case, the cab itself is also designed to be large for the necessity of increasing the space therein. Further, in order to meet a demand for, for instance, reclining an operator seat without sliding the operator seat forward, a rear space inside a cab is necessarily increased, which requires a size increase of the cab.
As the size of the cab is increased, a cab frame is also necessarily increased in size, so that the cab frame cannot be entirely immersed in an electrodeposition bath. In view of the above, according to some techniques, it may be possible to divide a cab frame into a plurality of frame parts and to assemble the divided frame parts after being separately immersed in an electrodeposition bath to be coated. For the purpose of improving productivity (not coating), Patent Literature 1 suggests a technique of dividing a cab frame into two, which is applicable to cab coating.